Extra copies will only be issued as a special promotion in the following cases:
Users who own "Left 4 Dead" and then go on to purchase "Left 4 Dead + Left 4 Dead 2 Bundle" will receive an extra copy of "Left 4 Dead"
Users who own “Half-Life 2” and go on to purchase “The Orange Box” or the "Valve Complete Pack" will receive an extra copy of “Half-Life 2”.
Users who own “Half-Life 2: Episode One” and then go on to purchase the "Half-Life 2: Episode Pack”, “Valve Complete Pack” or “The Orange Box” will receive an extra copy of “Half-Life 2: Episode One”.
Users who own "Universe at War" and then go on to pre-purchase "Aliens vs. Predator" will receive an extra gift pass for “Universe at War”.
Users who purchase the available four pack for one of the following games will receive three extra copies to gift to friends:
a. Bioshock 2
b. Borderlands
c. Global Agenda
d. Left 4 Dead
e. Left 4 Dead 2
f. Madballs in Babo: Invasion
g. Serious Sam HD
h. Shattered Horizon
i. Zero Gear
These special promotions will allow you to send a gift pass for your extra copy to a friend who does not already own the game.
Limitations
“Half-Life 2” and “Half-Life 2: Episode One” are only eligible to receive extra copies once.
For example, if you own “Half-Life 2” and/or ”Half-Life 2: Episode One” and receive extra copies for your purchase of “The Orange Box”, you will not receive additional extra copies if you then go on to purchase the “Valve Complete Pack”.
Do all duplicate purchases on Steam work this way?
No. This special offer only applies to games or game packages listed above.